00010 ORG $2600 00020 LOADER EQU $E2A3 00030 FCC /OS/ Required for DOS Command 00040 BEGIN BRA START Go to Main Program 00050 STEP FCB 0 Drive Step Rate 00060 TRACKS FCB 40 Number of Tracks 00070 SIDES FCB 1 Number of Sides 00080 BAUD FCB 18 Printer Baud Rate 00090 COCO FCB 3 CoCo Version 00100 COLORS FCB 0 Text Color 00110 FCB 18 Backround Color 00120 SPEED FCB 1 Double Speed 00130 BOOTF FCC /STARTUP /File Name to Auto-Execute 00131 TRAX FCB 39 Highest Track Number Set Highest track number for use in patching DECB 00140 START LDA TRACKS Get Number of Tracks 00150 DECA Minus 1 00160 STA TRAX Set Highest Track Number Check for CoCo3. If CoCo1 or CoCo2 then ROM must be copied into RAM 00170 LDA COCO Get Computer Type 00180 BNE COCO3 If CoCo 3 then skip ROM Copy 00190 ORCC #$50 Disable Interrupts 00200 LDX #$8000 Point to Beginning of ROM 00210 ROMRAM CLR $FFDE Enable ROMS 00220 LDD ,X Get Two Bytes 00230 CLR $FFDF Switch to All RAM Mode 00240 STD ,X++ Write Two Bytes and advance 00250 CMPX #$E000 End of ROMs? 00260 BNE ROMRAM If no then Loop 00270 ANDCC #$AF Enable Interrupts 00280 LBRA SLOW Skip CoCo 3 specific routines CoCo3 Only. Set Text and Background colors 00290 COCO3 LDD COLORS Get Text and Background Colors 00300 STD $FFBC Palette 12 & 13 00310 STA $FFB8 Palette 8 00320 STB $FF9A Border Color 00330 STB $FFB0 Palette 0 00340 STB $E035 Background Color for 32-column 00350 STB $E03E Background Color for 40-column 00360 STB $E047 Background Color for 80-column 00370 STB $E073 Background Color for 320*192 00380 STB $E07C Background Color for 640*192 CoCo3 Only. If Hi-Speed mode is set. Modify the DSKCON routine to switch to "Normal" Speed for Disk I/O and switch back to High Speed at completion of I/O. 00390 LDA SPEED "1" For Double Speed Mode 00400 BEQ SLOW If Not double speed then skip 00410 LDD #$7EC1 Modify DSKCON Entry Point DSKCON Entry point jumps to $C139 (Originally Disk Basic "Sign-on" message) 00420 STD $D75F $D75F JMP $C139 00430 LDA #$39 $D78C NOP 00440 STA $D761 $D78D NOP 00450 LDD #$1212 $D78E NOP 00460 STD $D78C 00470 STA $D78E 00480 LDD #$34F5 Save registers Get new Return From Subroutine Vector Put it on the Stack Switch to Slow Speed 5 Retries Resume processing from DSKCON routine 00490 STD $C139 $C139 PSHS PC,U,Y,X,B,CC 00500 LDA #$CC $C13B LDD $C148 00510 STA $C13B $C13E STD 8,S 00520 LDD #$C148 $C140 CLR $FFD8 00530 STD $C13C $C143 LDA #5 00540 LDD #$ED68 $C145 JMP $D763 00550 STD $C13E 00560 LDD #$7FFF 00570 STD $C140 00580 LDD #$D886 00590 STD $C142 00600 LDD #$57E 00610 STD $C144 00620 LDD #$D763 00630 STD $C146 00640 LDD #$7FFF Switch back to Fast at new Return Vector Return 00650 STD $C148 $C148 CLR $FFD9 00660 LDD #$D939 $C14B RTS 00670 STD $C14A 00680 LDD #$BDC1 New Vector for "Check Drive Ready" 00690 STD $D5FE $D5FE JSR $C14C 00700 LDA #$4C 00710 STA $D600 00720 LDD #$7FFF Switch to Slow Speed Jump to "Wait For Busy" 00730 STD $C14C $C14C CLR $FFD8 00740 LDD #$D87E $C14F JMP $D7D1 00750 STD $C14E 00760 LDD #$D7D1 00770 STD $C150 Common Routine for all CoCos 00780 SLOW JSR SETSTP Go Set Step rate 00790 JSR MOVELD Go move Loader Routine Main Routine 00800 PARSE0 JSR INPDIR Input the directory 00810 BRA PARSE1 Skip keyboard input 00820 PARSE JSR KEYSCN Read Keyboard 00830 PARSE1 CMPA #'Q "Quit?" 00840 BNE NOTQ If no then skip Exit to BASIC 00850 XIT CLR $2600 Clear first program byte 00860 JMP $AD17 Jump to BASIC NEW command Load a Program with SPACEBAR or ENTER 00870 NOTQ CMPA #32 "Spacebar?" 00880 BEQ GOLOAD If yes, load a program Set Drive Number 00890 CMPA #'0 Is it less than "0" 00900 BLT NOTNUM If yes then skip 00910 CMPA #'3 Is it greater than "3" 00920 BGT NOTNUM If yes, then skip 00930 SUBA #48 Convert ASCII value to number 0, 1, 2, or 3 00940 STA DRIVE New current drive 00950 BRA PARSE0 loop to read new directory Load A Program with ENTER or SPACEBAR 00960 NOTNUM CMPA #13 "Enter?" 00970 BNE PARSE If no, then loop 00980 GOLOAD LDU #PARSE0 Save a restore point 00990 JMP LOADER Go Load a program Set Step Rate 01000 SETSTP LDA STEP Step Rate for 01010 STA $D7C0 Restore head to track 0 01020 ADDA #20 Step rate for 01030 STA $D816 Seek Command 01040 ADDA #$3C Step rate for 01050 STA $D613 Step In Command Set Tracks 01060 LDA TRAX Last Track Number 01070 STA $D534 Error for DSKI$ or DSKO$ 01080 INCA Number of Tracks 01090 STA $D65F FORMAT completed? 01100 STA $D682 VERIFY completed? 01110 STA $D29D BACKUP completed? 01120 DECA Last track number 01130 ASLA Calculate Granules 01140 STA $C735 "Zero" bytes not in GAT 01150 STA $C7BB Copy GAT to GAT buffer 01160 STA $C7D0 Find free granules 01170 STA $C7EF Find Free Granules 01180 STA $CD26 Directory ?FC Error 01190 STA $CEB5 FREE command 01200 STA $D44D Check Disk Full 01210 SUBA #$44 Calculate Bytes for GAT image 01220 ASLA Calculate Bytes for GAT image 01230 ADDA #$4A Calculate Bytes for GAT image 01240 STA $C75A Find GAT for each drive 01250 CLR $800 Old GAT Location 01260 STA $801 Now temporary storage Set Single or Double sided drives 01270 LDA SIDES Get number of sides 01280 CMPA #2 Double sided? 01290 BNE ONESID If no, then skip 01300 LDD #$4142 Back side masks 01310 BRA SETSID Go set the sides 01320 ONESID LDD #$440 single side mask 01330 SETSID STD $D89F Save in drive masks for #2 & #3 New GAT image. Old table was too small. 01340 LDD #$FA0C Location of new GAT image table 01350 STD $C75D Patch DOS 01360 TFR D,X Save beginning of table 01370 ADDD $800 Add length of drive 0 01380 ADDD $800 Add length of drive 1 01390 ADDD $800 Add length of drive 2 01400 ADDD $800 Add length of drive 3 01410 STD $800 Save in temporary Storage 01420 CLRFAT CLR ,X+ Erase byte of GAT 01430 CMPX $800 Reached the end? 01440 BNE CLRFAT If No, then loop Set Printer Baud rate 01450 LDA BAUD 01460 STA 150 Find a Free Garnule. Patched because Numbers greater than 127 are Negative Jump to new routine Check if free No Operation 01470 LDD #$BDC1 01480 STD $C7C8 $C7C8 JSR $C152 01490 LDD #$5227 $C7CB BEQ $C7FD 01500 STD $C7CA $C7CD NOP 01510 LDD #$3012 01520 STD $C7CC 01530 LDD #$3402 Save Register Convert Poointer in B register to 16 bits so that it is not negative Get Granule Test if free Restore register and return 01540 STD $C152 $C152 PSHS A 01550 LDD #$4FA6 $C154 CLRA 01560 STD $C154 $C155 LDA D,X 01570 LDD #$8B43 $C157 COMA 01580 STD $C156 $C158 PULS A,PC 01590 LDD #$3582 01600 STD $C158 01610 LDD #$BDC1 Fix "Head-Banging" issue when using double-sided drives Patch Restore to track 0 routine Jump to fix No operation 01620 STD $D7B8 $D7B8 JSR $C15A 01630 STD $D7FF $D7BB NOP 01640 LDD #$5A12 01650 STD $D7BA Patch Seek routine Jump to fix No Operation 01660 STD $D801 $D7FF JSR $C15A 01670 STB $D7BC $D802 NOP 01680 STB $D803 01690 LDD #$8E09 The actual fix Get current track Get Current Drive Mask Drive 0 & 2 to be same. Same for Drive 1 & 3 Return to calling routine 01700 STD $C15A $C15A LDX #$97E 01710 LDD #$7ED6 $C15D LDB <$EB 01720 STD $C15C $C15F ANDA #1 01730 LDD #$EB84 $C161 RTS 01740 STD $C15E 01750 LDD #$139 01760 STD $C160 01770 RTS Clear the Screen 01780 CLS PSHS X,A Preserve the registers 01790 LDA #96 Blank Character 01800 LDX #$400 Beginning of Text Screen 01810 STX $88 Save in Screen Pointer 01820 CLS1 STA ,X+ Clear a byte 01830 CMPX #$600 End of screen? 01840 BNE CLS1 If no, then loop 01850 PULS A,X,PC Restore registers and return Print to Device -3 = DLOAD, -2 = Printer, -1 = Cassette, 0 = Screen, 1 - 15 = Disk 01860 PRINT STA $6F Set Device 01870 PRINT1 LDA ,U+ Get a byte 01880 BEQ PRINTX If 0, then exit 01890 JSR [$A002] Send byte to device 01900 BRA PRINT1 Loop 01910 PRINTX RTS Return to calling routine Disk I/O Read a Sector 01920 DISKIN PSHS B,A Preserve registers 01930 LDA #2 Read sector command 01940 LDB DRIVE Get Source Drive number 01950 BRA DISKIO Go do Disk I/O Write a Sector 01960 DISKOU PSHS B,A Preserve registers 01970 LDA #3 Write Sector Command 01980 LDB DDRIVE Get Destination Drive Number Main I/O Routine 01990 DISKIO LDY $C006 Get DSKCON Variables 02000 STD ,Y Command and Drive 02010 PULS A,B Get Track and Sector 02020 STD 2,Y Send to DSKCON 02030 LDX #$400 I/O Buffer (Text screen) 02040 STX 4,Y Send To DSKCON 02050 JSR [$C004] Execute Command 02060 PSHS U,X Preserve Registers 02070 LDA 6,Y Get Error Status 02080 BEQ NOERR Jump if no error Error Handler 02090 CLRB Set Count to 0 02100 FINDER LSRA Check Error Bit 02110 BLO GOTERR If error found then display it 02120 INCB Next Error 02130 BRA FINDER Loop until error found Display Error 02140 GOTERR ASLB Multiply error number by 2 02150 LDX #ERRTAB Point to Error Table 02160 LDU B,X Point to Error Message 02170 LDA #13 Carriage Return 02180 JSR [$A002] Print it 02190 CLRA Print device is screen 02200 JSR PRINT Print Error Message 02210 LDU #CONT "Press key to Continue" 02220 CLRA Print Device is Screen 02230 JSR PRINT Print message 02240 PAUSE JSR [$A000] Read keyboard 02250 BEQ PAUSE If no keypress, then loop 02260 NOERR PULS X,U,PC Restore registers and return Variables for Disk I/O 02270 DRIVE FCB 0 02280 DDRIVE FCB 0 02290 ERRTAB FDB ERR1 02300 FDB ERR1 02310 FDB ERR2 02320 FDB ERR3 02330 FDB ERR4 02340 FDB ERR5 02350 FDB ERR6 02360 FDB ERR7 02370 ERR1 FCC /UNDEFINED DISK ERROR/ 02380 FCB 0 02390 ERR2 FCC /LOST DATA ERROR/ 02400 FCB 0 02410 ERR3 FCC /CRC ERROR/ 02420 FCB 0 02430 ERR4 FCC /RECORD NOT FOUND/ 02440 FCB 0 02450 ERR5 FCC /WRITE FAULT ERROR/ 02460 FCB 0 02470 ERR6 FCC /WRITE PROTECT ERROR/ 02480 FCB 0 02490 ERR7 FCC /DRIVE NOT READY/ 02500 FCB 0 02510 CONT FCB 13 02520 FCC /PRESS ANY KEY TO CONTINUE/ 02530 FDB $D00 Read disk directory 02540 INPDIR LDD #$1103 Track 17, sector 3 02550 LDU #$E00 Directory Buffer 02560 NXTSCT JSR DISKIN Go get a sector 02570 NXTDIR LDA ,X+ Get byte from I/O Buffer 02580 BEQ KILLED If 0, then file was killed 02590 CMPA #255 If $FF then last entry 02600 BEQ NOMORE Go Process the Directory 02610 LDB #16 16 bytes of directory data 02620 MOVDIR STA ,U+ Save byte in Dir. Buffer 02630 LDA ,X+ Get another byte 02640 DECB All 16 done? 02650 BNE MOVDIR If no the look 02660 BRA SKIP16 End of directory entry 02670 KILLED LEAX 16,X Skip Killed File entry 02680 SKIP16 LEAX 15,X Skip unused bytes in Dir. 02690 CMPX #$4FF End of I/O Buffer 02700 BLT NXTDIR If No the loop 02710 LDD 2,Y Get Track and Sector 02720 INCB Next Sector 02730 CMPB #19 End of track? 02740 BNE NXTSCT If no, go get another sector Process Directory Check for Autoexec File 02750 NOMORE STU BUFEND Save end of Directory Buffer 02760 LDX #$E00 Beginning of Directory Buffer 02770 TSTBOO LDD ,X Get first two byres 02780 CMPD BOOTF Match 1st 2 bytes of Auto Start? 02790 BNE NOBOOT If no, go display directory 02800 LDD 2,X Get second two bytes 02810 CMPD BOOTF+2 Match 2nd 2 bytes of Auto Start? 02820 BNE NOBOOT If no, go display directory 02830 LDD 4,X Get third two bytes 02840 CMPD BOOTF+4 Match 3rd 2 bytes of Auto Start? 02850 BNE NOBOOT If no, go display directory 02860 LDD 6,X Get last two bytes 02870 CMPD BOOTF+6 Match last 2 bytes Auto Start? 02880 BNE NOBOOT If no, go display directory 02890 JMP LOADER LOAD & RUN / LOADM & EXEC 02900 NOBOOT LEAX 16,X Go to next entry 02910 CMPX BUFEND End of directory buffer? 02920 BLT TSTBOO If no, check another file Display Directory 02930 CLR PAGE Set directory page to 0 02940 NEWPAG LDU #$E00 Directory Buffer 02950 CMPU BUFEND Is it Empty? 02960 BNE WRITE If no, then display page 02970 JSR CLS Clear the Screem 02980 LDU #MT "Disk is Empty" 02990 CLRA Print device is screen 03000 JSR PRINT Print message 03001 PULS U Clear stack 03005 LBRA XIT Return to BASIC 03050 WRITE LDB PAGE Get Directory Page 03060 SRCHPG DECB Check if current page found 03070 BMI GOTPAG If yes, go display it 03080 LEAU $200,U Go to next page 03090 BRA SRCHPG Loop and Check if current page 03100 GOTPAG STU CURPAG Pointer to current page buffer 03110 JSR CLS Clear the screen 03120 NXTENT LDX $88 Get Text Screen Pointer 03130 LEAX 1,X Plus 1 03140 STX $88 Update Text Screen Pointer 03150 BSR FILNAM Display the File Name 03160 LDD $88 Get Text Sctrrn Pointer 03170 CMPD #$5F0 End of screen? 03180 BGE PAGEND If Yes go wait for user input 03190 LDD #$2003 "SPACE" three times 03200 SPACE3 JSR [$A002] Print a space 03210 DECB All done? 03220 BNE SPACE3 If no, then loop 03230 LEAU 5,U Advance to next filename 03240 CMPU BUFEND End of Directory buffer? 03250 BLT NXTENT If no, get another entry 03260 BRA PAGEND Otherwise, wait for user input Display a File Name 03270 FILNAM LDB #8 8 bytes in file name 03280 BSR TOSCRN Go Print Them 03290 LDA #'. "Dot" 03300 JSR [$A002] Print it 03310 LDB #3 3 bytes in Extension 03320 TOSCRN LDA ,U+ Get a byte 03330 JSR [$A002] Print it 03340 DECB All Done? 03350 BNE TOSCRN If no, then loop 03360 RTS Exit Parse user commands 03370 PAGEND LDU #$400 Top of Text screen 03380 LDX CURPAG Current page of Directory Buffer 03390 KEYSCN LDA #126 Right arrow 03400 STA ,U Display ">" to left of filename 03410 INKEY JSR [$A000] Read keyboard 03420 BEQ INKEY If no keypress, then loop 03430 CMPA #'^ Up Arrow? 03440 BEQ UP If yes, go process up arrow 03450 CMPA #10 Down Arrow? 03460 BEQ DOWN If yes, go process down arrow 03470 CMPA #8 Backspace? 03480 BEQ LEFT If yes, go process backspace 03490 CMPA #9 Right Arrow 03500 BEQ RIGHT If Yes, go process right arrow 03510 CMPA #$5F Shift up arrow? 03520 BEQ SHFTUP If yes, go process S. up arrow 03530 CMPA #'[ Shift down arrow? 03540 BEQ SHFTDN If yes, go process S. down arrow 03550 CMPA #3 BREAK? 03560 LBEQ INPDIR If yes, Load new directory 03570 RTS Return to calling routine Up Arrow 03580 UP BSR ERASE Erase the Cursor 03590 CMPU #$410 Top of Text Screen? 03600 BLE KEYSCN If Yes, ignore arrow 03610 LEAU -32,U Move up 1 row on screen 03620 LEAX -32,X Move back two files in directory 03630 BRA KEYSCN Go parse another command Down Arrow 03640 DOWN BSR ERASE Erase the Cursor 03650 CMPU #$5E0 Bottom of Text Screen? 03660 BGE KEYSCN If Yes, ignore arrow 03670 TFR X,D Move position to accumulator 03680 ADDD #32 Skip two filenames 03690 CMPD BUFEND End of Buffer? 03700 BGE KEYSCN If Yes, ignore arrow 03710 LEAU 32,U Move up 1 row on screen 03720 TFR D,X Update Directory buffer 03730 BRA KEYSCN Go parse another command Left Arrow 03740 LEFT BSR ERASE Erase the Cursor 03750 CMPU #$400 Beginning of Text Screen? 03760 BEQ KEYSCN If Yes, ignore arrow 03770 LEAU -16,U Move back 1 file on screen 03780 LEAX -16,X Move back one file in directory 03790 BRA KEYSCN Go parse another command Right Arrow 03800 RIGHT BSR ERASE Erase the Cursor 03810 CMPU #$5F0 End of Text Screen? 03820 BEQ KEYSCN If Yes, ignore arrow 03830 TFR X,D Move position to accumulator 03840 ADDD #16 Skip a filename 03850 CMPD BUFEND End of Buffer? 03860 BGE KEYSCN If Yes, ignore arrow 03870 LEAU 16,U Move forward 1 file on screen 03880 TFR D,X Update Directory buffer 03890 BRA KEYSCN Go parse another command Erase Cursor 03900 ERASE LDB #96 Blank character 03910 STB ,U Send to screen 03920 RTS Return to calling routine Shift Up Arrow 03930 SHFTUP LDA PAGE Get current directory page 03940 LBEQ INKEY If page 0 then ignore arrow 03950 DECA Previous page 03960 STA PAGE Save it 03970 LBRA NEWPAG Display new page Shift Down Arrow 03980 SHFTDN LDD CURPAG Get current Directory buffer 03990 ADDD #$200 Next page of data 04000 CMPD BUFEND End of directory buffer? 04010 LBGT INKEY If yes then ignore arrow 04020 INC PAGE Next page 04030 LBRA NEWPAG Display new page Variables for Directory display 04040 BUFEND RMB 2 04050 CURPAG RMB 2 04060 PAGE RMB 1 04070 MT FCC /DISK EMPTY/ 04080 FCB 13 04100 FDB $D00 Moves Loader Routine to "safe" area where it shouldn't be overwritten when loading a program. 04110 MOVELD LDX #LOAD Loader Routine 04120 LDU #LOADER New Location 04130 MOVE1 LDA ,X+ Get a byte 04140 STA ,U+ Save it 04150 CMPX #DATA All done? 04160 BNE MOVE1 If no, then loop 04170 LDX 25 BASIC program pointer 04180 LEAX -1,X One byte before BASIC program 04190 CLR ,X Make program invalid 04200 RTS Return to calling routine LOADs and RUNs a BASIC Program, or LOADMs and EXECutes a Machine Language Program 04210 LOAD LDA 11,X File type bit 04220 BEQ BASPGM If 0, then LOAD a BASIC Program 04230 CMPA #2 Is it Binary? 04240 BEQ MLPGM If yes, then LOADM a M/L Program 04250 PSHS U Preserve register 04260 JSR CLS Clear the screen 04270 LDU #DATA "Not loadable data" 04280 CLRA Print device is screen 04290 JSR PRINT Display message 04300 WAIT JSR [$A000] Read keyboard 04310 BEQ WAIT If no keypress then loop 04320 PULS U Restore register 04330 JMP ,U Go Back to Main Routine LOAD a BASIC Program 04340 BASPGM LDD #$300 Flags for LOADing 04350 STA $959 3 = Close all files and RUN 04360 STB $95E 0 = Do not merge 04370 BSR XFERNM Go Transfer File Name 04380 JMP $CA6C RUN"FILENAME.EXT" LOADM a M/L Program 04390 MLPGM BSR XFERNM Go Transfer File Name 04400 JSR $CA07 Open File For Input 04410 JSR $CFE3 Load file into memory 04420 CLR $FF40 Turn off Drive motors 04430 JMP [$9D] EXECute the program Transfer file name to Filename Buffer 04440 XFERNM LDA DRIVE Get Drive Number 04450 LDY $C006 DSKCON Variables 04460 STA 1,Y Store Drive # in variable 04470 LDU #$94C Get BASIC's Filename Buffer 04480 LDB #11 11 bytes of filename 04490 XFERLP LDA ,X+ Get a byte 04500 STA ,U+ Store in Buffer 04510 DECB All done? 04520 BNE XFERLP If no then loop 04530 RTS Exit Data for File Loader 04540 DATA FCC /SELECTED FILE IS NOT A LOADABLE/ 04550 FCB 13 04560 FCC /PROGRAM./ 04570 FCB 13 04580 FCC /PRESS ANY KEY TO CONTINUE./ 04590 FDB $D00 04600 END BEGIN